Telephone substation system



May E34., F. LUBBERGER 'y 13957559 TELEPHONE SUBSTATION `SYSTEM FiledNov. 23. 1,932 2 Sheets-Sheet 1 May 8, 1934n F. LuBaERGl-:R 1,957,659

TELEPHONE SUBSTATION." SYSTBI Filed Nov.2:s. 1932 2 sheets-sheet ze? Patented May 8, 1934 UNITED STATES PATENT OFFICE 1,951,659 TELEPHONE sUs'rArroN SYSTEM Application November 23, 1932, Serial No. 644,031

20 Claims.

The invention relates to circuit arrangements for telephone substation systems in which the subscribers are in a position to receive incoming exchange calls as well as to switch other substation subscribers calls over to their own line.

The object of the invention is to ensure a satisfactory operation in such systems by providing the private branch exchanges with devices which will enable the subscribers themselves to choose whether theyv wish to receive an incoming exchange call over the exchange line or prefer to switch an existing connection with another subscriber over to their own line.

An embodiment of the invention is shown in the accompanying drawings:

Fig. l shows a substation telephone line and a pair of nder switches AS and HW in which this line terminates.

Fig. 2 shows the final selector LW linked to the finder switches AS and HW and having access to the trunk line ab.

Completing an incoming exchange connection Upon the exchange calling a substation subscriber over the line ab, the alternating current sent out from the exchange energizes relay AR over windings I and II so that it closes its contact lar and consequently remains energized over: earth, battery, winding III, contacts lar, 2a, earth, and by opening its contact 56ar prevents the exchange line from being seized for an outgoing call. The closing of contact lar at the same time closes the following circuit for the lamps L1 and L2 associated with the exchange line taken into use: earth, contacts 2a, lar, lamp Ll or L2, battery, earth. These lamps Ll or L2, which are located, respectively, at stations desighated to receive incoming calls, operate no matter which particular subscriber of the system is being called. Exchange call signal lamps may also be provided for all the subscribers so that each substation can receive an incoming exchange call. A subscriber, for example T to whom the lamp L1 has been allocated, then receives the call by lifting his receiver. The two-step relay R ls energized over: earth, contacts 3T, 4a, the T-subscribers line loop, contacts 5q, 6r, winding I of relay R, battery, earth.l This relay R is energized in its rst stage only and consequently only opens its contact 91' and closes 71- and 81'. The closing of contact 81' prepares the test circuit over the c-wiper of the call nder AS, whereas contact '7T closes a circuit for relay C as follows: earth, contacts 71, 101, llpa, 12pl, relay C, batti'y, earth. Relay C is, energized and by Germany January 27, 1932 means of contact 13o closes the following circuit for the rotary magnet DAS: earth, contacts 13e, 14g, 151m, 16das, rotary magnet DAS, battery, earth. The rotary magnet DAS actuates its contact ldas and by means of this contact opens the above-described circuit for the rotarymagnet, so that they interact with each other and form a so-called self-interrupter circuit. K The wipers of the call nder AS are continuously advanced until the test circuit prepared by contact 81- is completed. Said test circuit extends as follows: earth, contacts 17e, 18u, windings I and II of relay PA, c-wiper of the call iinder AS set to the T-subscribers line, contacts 8T, 19a, Winding II of relay R, battery, earth. Relay PA is energized in this circuit and by means of contact l5pa opens the circuit for the rotary magnet DAS, at the same time short circuiting its winding I at contact 20pa for the purpose of guarding the subscribers line. In addition, relay R is energized in its second stage in the test circuit. This causes the calling circuit to be cut off at contacts 31 and 6r. Contact 10r is opened and prevents operation of the second call nder UAS accessible over Contact 311m. The opening of contact 101 causes relay C to relapse but contact 32k maintains the test circuit independent of contact 17o due to the fact that relay J is energized over the subscribers line loop on the closing of contacts 221m and 23pa and relay K also operates over: earth, battery, relay K, contacts 34j, 30PZ, earth. With the aid of relay PA the switch HW also is set to the subscribers line in the following manner: Relay PA causes the rotary magnet DHW of the switch HW to operate over: earth, contacts 26u, 271m, 28pa, 29dhw, rotary magnet DHW, battery, earth. In conjunction with contact 29dhw the rotary magnet operates as a self-interrupter and advances the wipers of the switch HW until the following circuit has been completed over the d-wiper of HW and the e-wiper of AS: Alternating current source of supply W, relay PH, d-wlper of HW, e-wiper of AS alternating current source of supply. Relay PH is an alternating current relay which, when energized, cuts off the circuit for the rotary magnet DHW of HW by opening its contact 271m.

The lighting of the lamp L1 indicates to the subscriber T that the call has been put through over the line connected to contact 3 of the final selector LW. In order to set the flnal selector, LW to this contact 3 the calling subscriber has to transmit three impulses which influence relay J. This relay in turn causes the rotary magnet DLW of the iinal selector LW to operate over:

earth, contacts 3091, 331i, 34e, 35k, rotary magnet DLW, battery, earth. The circuit for relay K is `cut off at contact 31j during the transmission of :the three impulses but relay K in spite thereof tains the test circuit for the final selector LW open at Acontact 37o, Relay V releases at the end of the impulse series and the following test circuit for relay PL is then closed: earth, contact 37o, windings I and II of relay PL, c-wiper of thev final selector LW in position 3, contacts 38ar, 39sp, resistance W, battery, earth. Relay PL is energized in this circuit and by short circuitingits winding I at contact 40p! guards the seized line in known manner. Relay PL maintains relay K energized over contact 41p! independent of relay J while relay J is disconnected from the speaking leads due to the opening of contacts 42151 and 43p! and, by the closing of 44p! and 45pl, these leads are switched through in the final selector. The closing of contact 46p! causes a fresh call initiation to be transferred to a second call finder IIAS when relay PA also is restored to normal during the connection as described in a later 93138111911. Bythe change-over operation on the part of contacts 42pl--45pl, the feeding of the subscriber's line is effected over the exchange line. Relay A connected to the b-lead is energized and at contact 2a opens the locking circuit for relay AR and also the circuit for the signal lamps L, thus indicating to the subscriber T that he has been connected to the exchange line. Relay A maintains the test circuit over the c-wiper of the final selector over contact 46a independent of contact 38er." The opening of contact 47a and closing of 48a prevents a connection from being set up in the outgoing direction which might otherwise be accomplished by the tlnal selector being set to contact 9.

'I'he connection with the calling exchange subscriber is now completed. If the subscriber who thus has been set to the calling exchange line is in a position to receive the call, no further switching operations are performed until at the end of the conversation when, on the receiver in the subscriber's station T being replaced, relay A restores and at contact 46a cuts off the circuit for relay PL. This relay at contact 41p! opens the locking circuit for relay K which in turn breaks the test circuit for the call finder at contact 32k. This causes relays PA and R to release. The rotary magnet DAS of the call ilnder AS operates over: earth, contact 49m, f-wiper of AS, contact l5pa, ldas, rotary magnet DAS, battery, earth, and continues to advance the wipers of AS until they reach their normal position in which the' Setting up an outgoing exchange connection Should the subscriber T require an exchange connection the can ander As 1s set to the calling subscriber in the manner previously described. 'I'he subscriber, however, contrary to incoming calls, has to' transmit seven impulses instead of three. These impulses influence relay J and consequently also the rotary magnet DLW of the linal selector in the same way as in the previous case. 'Ihe final selector is set to the 7th contact and at the end of the impulse series relay V, in the manner already described, is deenergized so that the following circuit is closed: earth, contact 37v, windings I and II of relay PL, c-wiper of the final selector LW in position 7, relay E, contact 53pI,y earth. Relay E only is energized in this circuit, opens its contact 36e and prevents an energization of relay V on the actuation of the rotary magnet DLW initiated by relay E over: earth, battery, rotary magnet DLW, contacts 35k, 54e, 51d1w, 50pl, d-wiper of the final selector LW set to the contact segment 55, earth. The rotary magnet advances the vwipers of the nal selector LW until they encounter an idle exchange line. It will be assumed that the exchange line connected to contact 9 is idle. The following circuit is then closed: earth, contact 37o, windings I and lI of relay PL, c-Wiper of the final selector LW in position 9, contacts 47a, 56ar, o'lsp, relay SP, battery, earth. Relay PL is the rst to operate in this circuit; opens at contact p! the circuit for the rotary magnet DLW, maintains over contact 4191 the circuit for relay K and due to the through-switching operation carried out by contacts 44321 and 45pl causes relay A to be energized. It should be noted that relay E is so retarded in its operation that on the advance from contact 7 it remains energized until all the contacts to which exchange lines are connected have been brushed in the iinal selector LW. Relay SP switches over the test circuit .for the final selector LW by opening contact 5731 and closing 58sp. After the switching through has been completed in the final selector,

. relay A connected to the b-lead has been energized and contact 58sp closed the test circuit extends over contacts 48a and 58sp. Relay SP opens contact 39sp, thus preventing the exchange line from being seiaed if another final selector is set to contact 3.

At the end of the call and after the receiver has been replaced in the subscribers station T, relay A restores and cuts oil the test circuit for the final selector LW at contact 48a. This at the same time breaks the circuit for relay SP which, however, releases with slow action and does not permit a fresh seizure until the iinal selector LW as well as the switch AS has been restored to normal in the manner described in `the previously specified method'of completing an incoming exchange connection.

Inquiry connections or transferring an exchnge call to another sub-station tact 59h, relay I, battery, earth. Relay B isrestored to normal when the subscriber T releases the depressed key and the following circuit for relay U is then closed: earth, contacts 60h 611,

uit

relay U, resistance W1, battery, earth. The circuit for relay I is cut oiI at contact 59h but this relay still remains energized until a locking circuit for relay U has been formed over contact 68g. Relay U causes relay Q to be energized over: earth, contact 62u, c-wiper ofthe switch HW set to the calling T-subscribers line, relay Q, battery, earth. Relay Q over its contacts 63a and 64q closes a circuit for relay F, extending as follows: earth, battery, winding I of relay Y, winding I of relay F, contact 65u., a-wiper of the switch HW set to the T-subscribers line, contact 64:1, the T-subscribers line loop, contact 63q, b-wiper of the switch HW set to the T-subscribers line, contact 66u, winding II of relay F, winding II of relay Y, earth. Relay F operates in this circuit. It transmits current to relay G over: earth, contact 67], relay G, battery, earth, so that relay U will be maintained energized over contact 68g in the following circuit: earth, contact 68g, relay U, resistance W1, battery, earth. Relay I does not release until relay G has operated and the locking circuit for relay U has been completed. Relay U, at contact 69u, connects a choke across the exchange line and thereby prevents the release of the exchange device.

Relay Q causes relay R to be maintained energized over: earth, contact 70q, winding II of relay R, battery, earth, and by opening contact vl9q cuts oiI the test circuit over the c-wiper of the call iinder AS so that relay PA relapses and the wipers of the switch AS are advanced'in the manner described above until they have been returned to their original position. Relay S which by opening contact r11s opens the test circuit for the call finder AS is energized in parallel with the rotary magnet DAS while said magnet operates. Immediately upon the switch wipers oi the call finder leaving the T-subscribers contact the circuit for relay PH is opened over the e-wiper, resulting in the release of relay PH. Relay YG causes a switching-over operation to be performed at contacts 'mg-75g. The sub scriber T is now in a position to set the call finder AS to the subscriber who is going to receive the exchange call. The subscribed T for the purpose of setting the switch AS transmits an appropriate impulse series which influences relay F. Relay F in turn transmits the impulses to the rotary magnet DAS over the following circuit: earth, contacts 7Bf, 77m, relay M, contact 78g, rotary magnet fDAS; battery, earth. Relay S, opening its contact 71s, is influenced in parallel with the rotary magnet DAS. Relay G due to its slow action does not relapse while contact 67j is intermittently opened according to the impulse series. At the end of this impulse series relay S is deenergized so that a test circuitunless the subscribers station is busy-can be completed, extending as follows: earth, contacts 79g, 71s, 80u, windings I and II of relay PA, contact 81m, d-wiper of the switch AS set to the contact associated with the subscriber required from the substation T, contacts 9r, 19q, winding Ii of the above-mentioned subscribers relay R, battery, earth. In this circuit relay R associated with the subscriber required from the substation T is first energized and due to the opening oi contact 91' and closing of 81 a test circuit is completed over'the c-wiper independent of the d-wiper of the switch AS and contact 81m. Relay PA completes the guarding by closing its contact 20pa and the switching through at contacts 22pa and 231m. The ringing signal to the required subscriber is transmitted in the mi@A lowing manner. Relay Fvcloses `the following circuit: earth, contacts 82f, 83o, relay N, relay interrupter RU, battery, earth. 'I'he relay interrupter RU causes relay N to be energized at deflnite intervals so that it applies` ringing current to the leads a and b by, opening its contacts 841: and 851i and closing 861i and 8711,. When the sub-v scriber accessible over the call finder AS lifts his receiver, relay Ol operates in the ringing pause in the following circuit: earth, battery, winding I of relay X, winding I of relay O, contacts 74g, 841i, 22pa, d-wiper of the switch AS set to the subscribers line, to whom the exchange call is being transferred over a corresponding contact 5q, subscribers line loop, contact 4a, b-wiper of AS, contacts 231m., 8411, g, winding II of relay O, winding II of relay X, earth. Relay O only operates in this circuit,and at contact /830 opens the circuit for relay N. Relay X is a d ierential relay and is not energized in series with relay O. The two substation subscribers are now connected with each other. Ii the subscriber who has been called over the switch AS wishes to take over the exchange call, this is carried out by momentarily depressing the key provided at the station reached over the switch AS. The momentary depression of this key causes the differential relay X in this subscribers feeding circuit to operate so that relay II in turn is connected to battery over: earth, contact 88x, relay II, battery, earth. Relay II is a slow acting relay and remains energized for a short time after relay X has been restored to normal on the release of the key Ta. When the subscriber releases the key Ta and before relay X restores, relay U is short circuited over contacts 89x and 9011 so that it relapses after a short period and at contacts 65u and 66u. opens the circuit for relay F. This relay, at contact 67j, opens the circuit for relay G, thus causing this relay G- to relapse. The change-over at contacts 'mg-75u is then restored and the speaking connection between the subscriber T and the other subscriber accessible over the switch AS is cut oil. The subscriber reached over the switch AS has now been connected to the exchange line. On the release of relay U the locking circuit for relay PA extends over contacts 32k, 18u, etc. At the same time relay U at contact 62u opens the circuit for relay Q, which opens its contacts 63a and 64:1 and closes Liq and 5q. The opening of contacts 70g deenergizes the T-subscribers relay R i! the subscriber T who was first connected to the exchange line meanwhile has replaced his receiver. Due to the release of relay U and the energization of relay PA in the test circuit for AS the rotary magnet DHW of the auxiliary switch HW is again energized and the switch HW is set to the subscriber to whom the subscriber T has transferred the call over the switch AS and in exactly the same manner as that previously described for the subscriber T. The circuit for the rotary magnet DHW is again opened on the energization of relay PH. At this moment the other subscriber is connected to the exchange line in the same manner as that in which the subscriber T was connected up before the transfer took place.

ierentlal relay Y in the test circuit to be energized. Relay Y at contact 79u opens the circuit for relay PA, which therefore restores and causes the switch AS set to the subscriber required 5 by the subscriber T to advance its switch Wipers until they have been restored to normal. The subscriber T now causes the switch AS to be set to his own line contact. He depresses his key Ta once more, thus causing relay Y to be reenergized and relay U to release due to short circuit in the following manner: Relay Y closes its contact S11/'and thereby causes relay I1 to operate over: earth, contacts 9111, 92u, 93ph, relay II, battery, earth. Relay II remains energized over contact 9411 independent of contact 92u. Relay I1 closes its contact 9011 and causes relay U to be short circuited over earth, contact 891: and 9011, whereupon it replapses after a short period. Relay U upon its release cuts off the circuit for relay Q.

Due to the release oi' relay Q the T-subscribers line is switched over from contacts 63q and 64q to 4q and 5q. Relay Q connects winding 11 of relay R to the c-wiper of AS over contact 81', so that a circuit for relay PA is closed as follows: earth, battery, winding II of relay R, contacts l9q, 8f, c-wiper of AS set to the subscriber T, windings II and I of relay PA, contacts 18u, 32k, earth. Relay PA causes the previously described switching operations such as the switching through, guarding, etc., to be performed.

The relapse of relay U causes the circuit for relay F which extends over contacts 65u and 66u to be cut off.

.When relay F is deenergized, relay G also relapses and the chanegover at contacts 729-759 is then, effected whereupon the subscriber T is again connected to the exchange line as prior to the enquiry connection being set up over the switch AS.

In addition, lt should be noted that relay II has a greatly retarded release withthe result that even after the subscribers line has been switched over from contacts 63a and 64q to contacts 4q and 5q, windings I and 1I of relay B are still short circuited at contacts 9511 and 9611 until relay II has been released and relay B consequently cannot be influenced as a result of the momentary depression oi the key and the already completed connection with the exchange line over the switch AS.

What is claimed is: 1. 1n a telephone system, two lines, a trunk, a switch, means controlled over one of said lines for operating said switch to connect the line with said trunk to answer an incoming call over said trunk, means controlled over said one line for reoperating said switch to interrupt the connection with the trunk and toestablish a connection between said two lines, and means controlled over the other o! said lines for operating said switch to interrupt the connection between the two lines and to establish a connection between said other line and said trunk to receive the incoming call.

2. In a telephone system, two lines, a trunk, a switch, means controlled over one of said lines for operating said switch to associate the line with said trunk to answer or extend a connection thereover, means controlled over said one line for reoperating said switch to establish a connection between said two lines and to hold up the trunk connection, and means controlled over the other o! said lines for interrupting the connection between the two lines ind for associating said other line with the trunk to take over the held-up connection.

3. A telephone system as claimed in claim l in which the switch is initially operated non-directively and reoperated directively.

4. A telephone system as claimed in claim 1 in which the reoperation of the switch is controlled jointly by a key and a calling device associated with the -line eiecting the initial operation of the switch.

5. 1n a telephone system, a nder switch and means for operating it to connect with a calling line, a second nder switch and means for operating it to connect with the calling line, and means controlled over the line for connecting the two finder switches together.

6. In a telephone system, a nder switch and means for operating it to connect with a calling line, a second iinder switch and means for operating it to connect with the calling line, means controlled over the line for interconnecting the two finder switches, and means responsive to said interconnection `for restoring the rst nnder switch to normal position.

7. In a telephone system, a finder switch and 10() means for operating it to connect with a calling line, a second nder switch and means for operating it to connect with the calling line, means controlled over the line for interconnecting the two nnder switches, and means controlled over the line for reoperating the llrst finder switch to extend a connection to a called line.

8. In a telephone system, two nder switches, means for operating both switches to connect with a calling line, means for releasing one switch while maintaining the connection with the other switch, and means for reoperating said one switch to extend a connection from the calling line to a called line.

9. In a telephone system, a line, a nder switch, means responsive to the initiation of a call on said line for operating said switch to connect with the line, a second ilnder switch, means controlled by said rstswitch for operating said second switch to connect with the line, means for momentarily unbalancing the line, and means responsive to said unbalance for releasing said ilrst switch and for connecting the two switches together.

10. In a telephone system, a first switch, a second switch normally connected with the ilrst switch, means for operating the first switch to connect a calling line with the second switch, means for operating the second switch to extend a connection, a third switch and means for operating it to connect with the calling line, means controlled over the line for disconnecting the first -switch from the second switch and for temporarily connecting the irst and third switches, and i means for holding up the connection extended through the second switch while the rst and third switches are interconnected.

11. In a telephone system, a first switch, a second switch normally connected to the rst switch, means for operating the rst switch to connect a calling line to the second switch, a third switch and means for operating it to connect with the calling line, means controlled over the calling line for disconnecting the rst switch from the second switch and for interconnecting the nrst and third switches, means controlled over the calling line for reoperating the ilrst switch toextend a connection to a called line, and means controlled over the calling line or the called line for disconnectingghe rst switch from the third switch and for reconnectingv it to the second switch.

12. In a telephone system, a rst switch, a second switch normally connected to the first switch, means for operating the rst switch to connect a. calling line to the secondY switch, a third switch and means for operating it to connect with the calling line, means controlled over the calling line for disconnecting the first switch cev from the second switch and for interconnecting the rst and third switches, means controlled over the calling line for reoperating the iirst switch to extend a connection to a called line, and

means controlled over the called line for disconnecting the first switch from the third switch, for reconnecting the rst switch to the second switch, and for operating the third switch to connect with the called line.

13. In a telephone system, two nder switches, means for operating one of said switches to hunt for and connect with a calling line, means controlled by said one switch for operating the other switch to connect with the line, means for releasing said one switch while maintaining the connection between the other switch and the line, and means controlled over the line for directively operating said one switch to extend a connection from the line to a called line.

14. In a telephone system, a line, a switch, means responsive to the initiation of a call on the line for operating the switch to hunt for and connect with the line, means for establishing an auxiliary connection between the switch and the line, and means controlled over the line and said connection for reoperating said switch to connect with a second line.

15. In a telephone system, two finder switches, a line having two branches, means responsive to the initiation of a call on the line for operating one switch to connect with one of said branches,

means responsive to said connection for operating the other switch to connect with the other of said branches, and means controlled over the line for controlling the connection of said branches to the line.

16. In a telephone system, two nder switches, a line having two branches, means responsive to the initiation of a call on the line for operating one switch to connect with one of said branches, means responsive to said connection for operating the other switch to connect with the other of said branches, and means for extending a connection from the line over said one branch and said one switch or over said other branch and both of said switches in tandem.

17. In a telephone system, a line, two finder switches, means responsive to the initiation of a call on the line for operating both switches to connect with the line, and means for completing the call through one switch alone or through the two switches connected in tandem.

18.,In a telephone system, a switch, a trunk having two branches, means for operating said switch to connect with the trunk via one branch to answer an incoming trunk call, and means for operating the switch to connect with the trunk via the other branch to extend an outgoing trunk call.

19. A telephone system as claimed in claim 18 in which the switch is entirely directive operated to connect with one branch of the trunk and is both directively and non-directively operated to connect with the'other branch of the trunk.

20. A telephone system as claimed in claim 18 in which the switch is one of a plurality of similar switches and is taken into use responsive to a subscriber lifting his receiver to answer or extend a call.

FRITZ LUBBERGER. 

